1. Field of the Invention
The present invention relates to a button and to portable equipment provided therewith, and more particularly to a button suitable to be installed in watches and other portable equipment.
2. Description of the Related Art
Operating buttons are commonly disposed on the external surface of a main body of a wristwatch, pocket watch, or other portable watch; or a stopwatch, dive computer, or other type of portable equipment. In such an operating button, the button member is normally mounted to protrude slightly from the external surface of the main body in a manner that allows entry and exit with respect to the base, and is configured so that the contact or the like within the main body operates by pressing this button member. Also, a lock mechanism for restricting the thrust action of the button member has been proposed for preventing operating button malfunctions (JP-A 2003-7164).
The operating button with a lock mechanism cited in JP-A 2003-7164 is provided with the configuration described below. In other words, a cylindrical fixed member (tube member) is inserted through and fixed in a through-hole disposed in the base (body), and the shaft portion of the button member is slidably inserted in the axial direction through the fixed member. In the button member, a head portion with an expanded-diameter portion is mounted on the external end of the shaft portion, and an elastic member having a coil spring is housed in a compressed manner between the head portion and the fixed member. A restricting surface facing in the external axial direction is provided in the form of a stepped cylinder to the shaft portion of the button member, and a lock member whose internal peripheral surface threadably engages the fixed member is inserted therethrough.
An operating button with a lock mechanism in such a configuration is constituted such that when the head portion of the button member is pressed with the fixed member threadably inserted deep into the base, the button slides in the axial direction so that the button member enters the base while compressing the elastic member, causing a contact or the like disposed inside the base to operate. Also, the configuration is such that when the lock member is rotated and withdrawn, the movement of the button member is restricted by the restricting surface of the lock member coming into contact with the inside of the head portion of the button member, preventing the button member from being unintentionally pressed by operational error.
However, there is a drawback in the operating button cited in JP-A 2003-7164 in that the lock member is required to be withdrawn to restrict the movement of the button member and the external appearance of the operating button differs in terms of the locked state and the unlocked state, resulting is a flawed design.
There is a further drawback in that by repeatedly rotating and pulling out or threadably inserting the externally exposed lock member, foreign matter or the like tends to enter in between the lock member and the base of the fixed member, and time is needed to keep the lock member in operating order.
In view of the above, it is apparent to those skilled in the art from the disclosure of the present invention that a need exists for an improved button. The present invention is one that provides for these requirements in the prior art, as well as for other requirements that will be made apparent to those skilled in the art through the following disclosure.